Saxagliptin [(1S,3S,5S)-2-[(2S)-2-amino-2-(3-hydroxy-1-adamantyl) acetyl]-2-azabicyclo[3.1.0]hexane-3-carbonitrile] and its hydrochloride salt are orally active reversible dipeptidyl peptidase-4 (DPP4) inhibitors, which are used as therapeutic agents for the treatment of type-2-diabetes mellitus, obesity, or related diseases. It is disclosed in example 60 of U.S. Pat. No. 6,395,767.
PCT application WO 2001068603 A2 discloses Saxagliptin in the form of its trifluoroacetate salt, as described in Example 60.
The processes for the preparation of Saxagliptin benzoate salt (scheme VII, Example 41), Saxagliptin free base and free base monohydrate (Example 42), and Saxagliptin hydrochloride (scheme VIIB, Example 42) are disclosed in the PCT application WO 2004052850 A2.
WO 2008131149 A2 discloses Saxagliptin free base, specific acid addition salts of Saxagliptin such as hydrochloride, hydrobromide, hydroiodide, ammonium sulfate, nitrate, benzoate, tartrate, fumarate and trifluoroacetate salts, and certain polymorphs, and hydrates thereof.
Methods of preparation of Saxagliptin hydrochloride are described in U.S. Pat. No. 7,214,702 B2 and in Organic Process Research & Development 2009, 13(6), 1169-1176.
PCT application WO 2010115974 A1 describes certain polymorphic forms of Saxagliptin hydrochloride.
CN 102086172 A discloses mesylate, maleate, malate, succinate and citrate salts of Saxagliptin.
PCT application WO 2012017028 A1 describes the phosphoric acid salt of Saxagliptin and its polymorphic forms.
PCT application WO 2012017029 A1 discloses crystalline forms of Saxagliptin salts with organic diacids such as form A of Saxagliptin maleate, form B of Saxagliptin L-malate, and form C of Saxagliptin succinate.